(a) Field of the Invention
The present invention relates to an assembly to secure a camshaft in an engine.
(b) Description of the Related Art
With reference to FIG. 1 which illustrates the prior art, a pair of camshafts 6 is provided in an upper portion of an engine 2 in a state where the camshafts 6 are substantially adjacent to one another. The camshafts 6 are rotated through their connection to a crankshaft sprocket and a timing belt (not shown), thereby acting to open and close intake and exhaust valves. An air-fuel mixture is supplied to combustion chambers of the engine 2 and undergoes combustion therein.
The resulting force drives pistons of the engine 2, that is, the pistons undergo a reciprocating motion within cylinders of the engine 2. This motion of the pistons rotates the crankshaft sprocket. As a result, a camshaft sprocket is rotated by its connection to the crankshaft sprocket through the timing belt such that the camshafts 6 are, in turn, rotated. With the rotation of the camshafts 6, intake cams and exhaust cams formed on the camshafts 6 operate to open and close the intake valves and exhaust valves, respectively.
A plurality of bearing caps 8 are mounted through bolts 16 directly over the camshafts 6 to secure the same, thereby minimizing vibrations of and the generation of noise by the camshafts 6. However, the securing of the camshafts 6 by the independently operating bearing caps 8 provides an insufficient force to firmly fix the camshafts 6. Accordingly, such a structure is not effective in minimizing the vibrations of the camshafts 6 or in preventing the generation of blow-by gas. In addition, the bearing caps 8 make assembly and disassembly difficult. For example, the bearing caps 8 must be mounted in the correct direction during assembly.
It is an object of the present invention to provide an assembly to secure camshafts in an engine, in which a significant force is applied by the assembly to fully secure the camshafts, thereby reducing vibrations and noise of the camshaft.
It is another object of the present invention to provide an assembly to secure camshafts in an engine that allows for easy assembly and disassembly of the camshafts.
In a preferred embodiment of the present invention, an assembly to secure engine camshafts comprises: a cylinder head provided with a plurality of concave parts into which the camshafts are placed, the concave parts allowing for rotation of the camshafts; and a full cam carrier mounted to the cylinder head over the camshafts and allowing for the rotation of the camshafts, the full cam carrier including a plurality of ribs corresponding to positions of the concave parts and integrally formed to the full cam carrier at predetermined intervals.
Preferably, the full cam carrier further comprises: a base frame fixedly connected to the cylinder head; a plurality of camshaft bearings mounted on the base frame; and an ignition unit connector formed along a length of the base frame at a longitudinal center thereof and including cavities to which ignition units over each cylinder are connected, wherein the ribs are connected on both sides of the ignition unit connector.
According to another preferred embodiment of the present invention, a width of each rib is wide enough to cover a pair of cams such that a substantial amount of noise of the camshafts can be prevented from leaking out.